1. Field of the Invention:
The present invention relates to a combinatorial weighing apparatus for producing a pack containing a number of articles of merchandise which have a total weight equal to a prescribed weight.
2. Description of the Prior Art:
As the standard of living becomes higher, more kinds of articles of merchandise, such as foods, in small and great quantities are found in the market and sold in various manners.
In supermarkets or the like, such articles of merchandise are not sold separately at random, but sold in packages of measured quantities so that they can easily be handled by the retailers and consumers. The measured quantities may be measured numbers or weights of articles.
In weighing articles to be sold, it is necessary that the measured weight should not be smaller than a prescribed weight which the consumer desires. However, any measured weight much larger than a prescribed weight is undesirable for the retailer. Therefore, it is ideal weighing practice to obtain a measured weight which is equal to a prescribed weight or approximates such a prescribed weight plus a minimum overweight. There has been a demand for measuring technology that articles be processed quickly and in large quantities according to such weighing operation. As disclosed in earlier applications assigned to the applicant, combinatorial measuring operation has been developed which is based on the theory of probability and statistics and high-speed computerized calculations, and which is improved for high-speed processing.
According to one combinatorial measuring process, articles after they have been processed by combinatorial measuring operation are packaged in bags of polyethylene. In many cases, measured articles are simply put into bags and packaged. Japanese Laid-Open Utility Model Publication No. 59-6732 and U.S. Pat. No. 4,553,617, however, disclose a procedure in which articles are weighed to meet a prescribed weight, and a prescribed number of such articles are charged into a package tray.
The conventional combinatorial weighing apparatus have a collection chute with a single lower discharge port. In order to charge articles into an array of package trays extending transversely to the direction in which they are fed, the collection chute has to be moved along the array of package trays as many times as the number of package trays. Therefore, a complex mechanism is needed to move the collection chute, and a frame and components of the apparatus having such a complex mechanism are large in size, resulting in a large-size apparatus. The large-size combinatorial weighing apparatus takes up a large space, and the well-balanced arrangement of the combinatorial weighing apparatus and surrounding devices operable in coaction therewith is difficult to achieve. Initial assembly and maintenance such as inspection, servicing, and the like of the apparatus are also difficult to accomplish. The combinatorial weighing apparatus produces vibration and large noise, and requires high initial and running costs.
In the above conventional combinatorial weighing apparatus, moreover, articles are caused to drop from weighing hoppers to package trays without substantial resistance. There is no problem with hard articles which will not be broken if they drop from the weighing hoppers through the collection chute into the package trays. However, soft articles may be collapsed by the shock when they impinge upon the package trays.